Existential psychotherapy is one of the longest-established forms of psychological intervention, but the scope and nature of the intervention remains unclear. To deepen an understanding of the nature of existential psychotherapy, an international survey was conducted of existential practitioners, asking them to identify the authors and texts that had most influenced their practice. Responses were received from practitioners in 48 different countries, with 1085 identifying the authors that had most influenced their practice, and 853 identifying the most influential texts. The six authors identified as most influential were Frankl (16.6 %), Yalom (15.5 %), Spinelli (10.6 %), van Deurzen (10.0 %), Längle (8.7 %), and May (5.9 %). The first four authors were also responsible for the six most influential texts: Man's Search for Meaning (Frankl, 9.4 %), Existential Psychotherapy (Yalom, 9.2 %), Practising Existential Psychotherapy (Spinelli, 3.5 %), The Doctor and the Soul (Frankl, 3.5 %), Everyday Mysteries (van Deurzen, 3.4 %), and Existential Counselling & Psychotherapy in Practice (van Deurzen, 3.2 %). These findings help to develop a greater understanding of the theoretical and practical influences on existential psychotherapy today.